The moon appears orange mainly because of Earth's atmosphere filtering the light it reflects. When the moon is near the horizon, its light passes through a thicker layer of Earth's atmosphere. This atmosphere scatters shorter wavelengths of light, such as blues and violets, more than the longer wavelengths like red and orange. As a result, the orange and red wavelengths dominate what we see, giving the moon an orange color. This effect is similar to why the sun appears orange or red at sunrise and sunset. Other factors that can make the moon look orange include the presence of particles in the air such as dust, pollution, or smoke from wildfires, which also scatter shorter wavelengths and let the longer, red/orange wavelengths pass through. The moon looks whiter or more silvery when it is high in the sky because the light passes through less atmosphere and less scattering occurs. In summary, the orange color of the moon is due to the scattering of light by the Earth's atmosphere, especially when the moon is low on the horizon or when the atmosphere contains additional particles that enhance this effect.
